In simplified Valence Shell Electron Pair Repulsion (VSEPR) theory, what causes atoms (bonding groups) to spread out around a central atom?

• A. Repulsion between electron groups (bonding pairs and lone pairs) around the central atom
• B. Neutrons in the nucleus repelling each other and pushing bonded atoms outward
• C. Increasing the number of protons in the nucleus, which forces bonds apart
• D. Attraction between electron groups that pulls them closer together

Answer: (A)

Verified step by step guidance

1. Understand that VSEPR theory explains the three-dimensional shape of molecules based on the repulsions between electron groups (bonding pairs and lone pairs) around a central atom.
2. Recognize that electron groups are negatively charged and repel each other due to electrostatic forces, which causes them to arrange themselves as far apart as possible to minimize repulsion.
3. Note that this repulsion between electron groups, not forces involving protons or neutrons in the nucleus, is the primary factor determining the geometry of the molecule.
4. Recall that lone pairs of electrons exert repulsion just like bonding pairs, often influencing the shape by pushing bonding pairs closer or further apart.
5. Conclude that the spreading out of atoms (bonding groups) around a central atom is caused by the repulsion between electron groups, which leads to the observed molecular shapes.